Recycling of the end-of-life lightweight aggregate concrete (LWAC) with a novel approach
Journal article, 2020

This work proposed an environmental-friendly approach for high-grade recycling of the end-of-life LWAC. The mechanical performance of mortar with recycled powder (RP), mortar with recycled fine aggregate (RFA) and recycled lightweight aggregate concrete (RLWAC) were investigated. Microstructure of mortar and RLWAC was detected to identify the properties of interfacial transition zone (ITZ). RP can prolong the setting of reference cement and the 10% dosage is better than 2% in not only retarding effect but also strength development. An appropriate content of RFA is beneficial for compressive strength. Replacing standard sand with 10% RFA increases the compressive strength of mortar by approximately 10%. However, a high replacement content (40%) of RFA brings about a reduction of compressive strength. The amount of RFA below 20% will not increase the dry shrinkage of mortar. The compressive strength of RLWAC is reduced by 10% RLWA but it has a significant increase when the replacement content reaches 30%. In mortar with RFA, cracks initiate from the ITZ of new sand and new paste and few cracks generate from old paste and old sand. Four types of ITZ that have distinct features are observed between cement paste and LWA in RLWAC.

Recycled powder

Interfacial transition zone

Recycled fine aggregate

Sustainable concrete

Recycled lightweight aggregate

Author

Liming Huang

Tongji University

Chalmers, Architecture and Civil Engineering, Building Technology

Zhenghong Yang

Tongji University

Zhen Li

Tongji University

Yafei Xu

Tongji University

Long Yu

Tongji University

Journal of Cleaner Production

0959-6526 (ISSN)

Vol. 275 123099

Subject Categories

Manufacturing, Surface and Joining Technology

Other Materials Engineering

Biomaterials Science

DOI

10.1016/j.jclepro.2020.123099

More information

Latest update

11/23/2020